Double bearing for bicycle sprockets and crank-shafts.



y A A.4 L. GIRARD'. DOUBLE BEARING FOR BICYCLE SPEOGKETS AND GBANKSHAFTS. APPLICATION FILED AUG. 31, 1908.

. In verffol` Q/. WIW-@1 www L gimra,

74;,5 Oilo meg.

ARTHUR L. GIRARD, OF'LINCOLN, NEBRASKA.

DoUBLnBnARi-Ne non :BICYCLE sPnooKETs AND (iRANK-SHAFTS.

Specification of Letters Patent.

Patented May 1 1, 1909.

Application led Augustrl, 1908. Serial No. 451,112.

To all rwhom it may concern: i

Be it known that I, ARTHUR L. GIRARD, a citizen of the United States,residing at Lincoln, in the county of Lancaster and State of Nebraska,have invented certain new and useful Improvements in Double Bearings forBicycle Sprockets and Crank Shafts, of which the following is aspecification sufficiently clear to enable those skilled in the art towhich it appertains to make and use th same. t

Its object is :-1. To produce separate sprocket and se )arate crankshaftbearings for bicycles whic bearings will eliminate side draft from theVsprocket, increase the distance a wheel will run without oiling anddecrease accordingly the danger of accidents due to dry bearings.' 2. Toprovide bicycle sprocket and crank shaft bearings in a direct line withthe pull and which work together greatly decreasing the friction andincreasing the wearing power and making the `wheel an exceedingly easyrunner. This purpose is attained in my invention by certain novelconstruction and combination of parts and materials which will behereinafter described and claimed. f

My invention is illustrated in the accompanying drawings The figurerepresents a vertical, cross-sec tional view (lengthwise the shaft) ofmy invention on bike frame.

A Similar letters refer to similar parts.

I make a double cup, b having a cylindrical portion terminating at oneend in an outer and an inner annular flange. I thread the outer side ofthe cylindrical portion of my double cup for the urpose of holding thecollar bearing i and or the further purpose of attaching the double cupto the bicycle frame. I attach my double cup by screwing its threadedend into threads cut into the crank hanger to receive saine, or byscrewing the threaded end of the doublecup -into a sleeve, the sleevebeing held in the crank hanger by lugs and inch bolts underneath thebracket preferab y. The inner, and annular side of each flange I shapeto fit the bearing mediums so that the outer bearing is directly overthe .inner bearing and both working on the same plane. In connectionwith the inner bearing medium I use an ordinary cone bearing d. `Inconnection with the outer bearing medium I use the collar bearing ithreaded to match the threads in the double cup and attached andadjusted thereby.

I make a track, or ball, race a to fit over the outer bearing mediums,for bearing mediums I prefer the ordinary balls, e, e, e, I make theouter part of the track, or ball, race a with an oset and a shoulder toreceive the sprocket f and I thread the lower portion of the outer partof the track race and attach the sprocket-wheel thereon and against theshoulder portion thereof by means of the lock-nut c so as to make thesprocket line with the two sets of bearings, e e. I provide a slot l ina spoke of the sprocket f. I provide the crank g with a lug 7c, the endof which lug passes loosely through the slot Z in sprocket spoke, thellug 7c being shaped land positioned so as to permit radial and lateralmotion in sprocket slot Z. I use a crank integral with a crank shaft g,Whichcrank shaft and crank is carried on the inner bearing mediums, mysprocket being carried on the outer set of bearing mediums, the setoutside the double cup. Thus my sprocket and its bearings outside thedouble cup and my crank shaft bearings inside the double cup work on thesame plane, each doing its own work. This feature is made possible andpractical by means of my transmission of power to the sprocket throughmy sliding lug device. The slot Z in the s rocket spoke I make longerthan the width of the lug lc, The lug 7c is attached solidly to thecrank arm g and positioned so as to pass through the slot l leavingspace above and below the lu in said slot. This device renders itimpossib e to transmit a side pull to my sprocket and impossible for myshaft to ride on my sprocket wheel or for my sprocket wheel to ride onmy shaft, enabling my construction to increase the life of a wheel,makes it an exceedingly easy runner, an ideal hill climber, increasesthe distance it will run without oiling, besides other incidentaladvantages all of which will be the more easily understood by anexamination of the figure of the drawings, `made a part of thisspecification. l

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is

. l. In bicycle gearing, a crank shaft provided with means of preventingendwise displacement, a crank hanger, a sprocket wheel provided With aslot in one ol its spokes, a crank integral with said crank shaft andhaving a lug loosely fitting the said slot, a double cup With an outerand inner annular flange 5 and having outer threads for engaging one endof the crank hanger and also i'or engaging a collar bearing, a ball raceprovided With an inner grooved surface to fit the bearing mediums ol'the sprocket bearings and provided With an outer surface litting thecentralopening in said sprocket, one side olf said outer surface beingthreaded, the other side formed-into a projecting shoulder, a threadednut lock fitting threads on said ball race, a

"th`readed collar bearing fitting threads on the double cup, a set ofsprocket bearing mediums positioned outside the double cup in line Withsaid sprocket, and a set ol` crank shaft bearing niediurns positionedinside the "double cup in line With said sprocket bear- With a slot inone ol its spokes, a crank shaft,

a crank integral `with said crank shait and having 'a lug looselyiitting the said slot, a double cup With an outer and an inner annularflange and having outer threads -lor enaging one end ol' the crankhanger and also or engaging a collar bearing, a ball race provided Withan inner grooved surface to lit the bearing mediums ol' the sprocketbearings and provided With an outer surface fitting the central openingin said sprocket, one side of said outer surface being threaded, theother side being forrned into a projecting shoulder, a threaded nut lockfitting threads onv said ball race, a threaded collar bearing 40 iittinthreads on said double cup, a set of sproc et bearing mediums positionedoutside t 1e double cup in line With said sprocket, and

a set oi crank shalt bearing mediums positioned inside the double cup inline with the sprocket bearing mediums and sprocket, all substantiallyas described.

3. ln bicycle gearing, in combination, a crank shaft, a crank hanger, asprocket wheel provided with a slot in one of its spokes, a

crank integral With said crank shaft and havf ing a lug loosely iittingthe said slot and pro jecting through the slot, leaving space thereinabove and below the lug, slidably connecting the crank and sprocket, adouble cup comprising a cylindrical portion terminating at one end in anouter annular l'lange and an inner annular ilange the cylindricalportion having outer threads l'or engaging one end ol' the crank hangerand ior engaging a collar bearing, a ball race having an inner groovedsurface to lit the sprocket bearing mediums and an outer surface ittingthe inner opening in said sprocket, one side ol said outer surface beingthreaded the other side having an annular shoulder projecting therefrom,a threaded nut lock Alitting said threaded outer surface, a threadedcollar bearing Vlitting threads on said double cup, a set oil snocketbearing mediums positioned outside the double cup in line with saidsprocket, and a set ci' crank shal't bearing mediums positioned insidethe double cup in line and working on the same plane with the procketbearing mediums and sprocket, the said sha'l't being provided with acone bearing, all substantially as described.

ln testimony whereof, l have signed .my naine to this specilication inthe presence ol' two subscribing Witnesses.

ARTHUR l). GNL/Utl).

W'itnesses:

H. F. BISHOP, MAY E. HOLLAND.

